Barbara researched Henry Crofts Sercombe in the hope that our Vlielands were banking there and guess what.
She received a letter from a very helpfull lady that reads
We have a record of a Thomas Vlieland, who was apparently a customer of Drummonds Bank in 1780. Drummonds is one of our private banks in London and we have an excellent set of customer ledgers which detail income and expenditure.
Thomas Vlieland's account only covers one year, so I don't know how interesting it would be even if he is related to your family, but I thought you might like to know that there was definitely a Vlieland in London in 1780!
I think this must be Thomas Michiel Vlieland .
He came from Belgium to settle in Zeeland a part of the Netherlands .
He bought and sold a house there .
He worked for the Dutch East India Company.
So maybe that is the reason for banking in London for one year.
He attended a funeral in Sri Lanka.
But so far that is all we know.